As my team and I do more and more research into making a reliable pneumatic system because our robot will rely heavily on pneumatics we realised the “stock” compressor kinda sucks. I know there is the CFM limit but is there any better compressors out there?
There have been a number of discussions about compressors in the past, the most recent one is here. The standby for me will always be the old Thomas compressor from the kit of parts, however we have purchased and really like the Viair 250C-IG (it’s significantly larger and heavier then the current KOP compressor).
As a caveat, the Viair above comes with a stainless steel hose that is required for operation by the manufacturer. The hose helps dissipate the heat generated by the compressor and compressed air.
We used the Vivair 90 last season on our robot and had no problems with it. The trick is to blow some air across the heat sink to keep it cool.
For reference most of our robot ran on pneumatics. Shifters, wings, pickup arm, and the catapult. We used a lot of air.
As I mentioned in another thread, my feeling is that this year, pneumatics will work fine for “grabbing”, but not for “lifting”. The amount of work that needs to be done to stack totes and containers is pretty high, and the compressor just can’t keep up with air demands.
I could be wrong, but you ought to at least do some power calculations. Be sure to derate the compressor’s flow rate for the pressure it will be operating at, there is a CFM vs PSI chart for it somewhere. And beware that pneumatics is a rather inefficient way to do work, there is lots of loss both in compressing the air, and in the cylinders moving back and forth. There are tricks you can play to help, but it will still probably be marginal. We had an almost fully pneumatic robot last year, with a much lighter game piece, and had trouble with running out of air.
Speed will be vital this year for getting lots of points, you don’t want to be waiting around for the compressor to build pressure.
MrForbes is right. You need to think very carefully about designs that need lots of air to work.
One thing we’ve done in the past to help the compressor out is to run a fan blowing on the heat sink. Not so much during matches as when you’re testing in the shop – most of the legal compressors are rated for very low duty cycles and get quite hot. We started doing this after we melted the tube leading from the compressor.